During the process of coal mining, discontinuous geological bodies, such as faults, fractures and collapsed columns, would destroy the continuity of coal seams, which is prone to inducing accidents such as water inrush and gas burst, and poses serious threats to the safety of coal mining operation. Therefore, it is of great significance to effectively identify the discontinuous geological bodies such as faults, fractures and collapsed columns.
At present, there are a lot of methods for identifying faults and fractures, including a seismic coherence technique (Bahorich and Farmer, 1995; Marfurt, et al., 1998, 1999; Gersztenkorn and Marfurt, 1999), a matching pursuit algorithm (Mallat and Zhang, 1993; Castagna et al., 2003; Liu and Marfurt, 2005), a spectral decomposition algorithm (Partyka et al., 1999; Puryear et al., 2012; Gao et al., 2013) and so on. However, due to characteristics, such as different sizes and irregular distribution, of the collapsed columns themselves, none of the above several methods could effectively identify the collapsed column. Therefore, identification of the collapsed column has always been a difficulty in seismic exploration.
In order to solve the above difficulty, a seismic wave imaging technique is adopted in the related art to identify the collapsed column, which specifically includes: collecting seismic shot gather data, imaging reflected waves in the seismic shot gather data with an existing seismic wave imaging technique, and identifying a collapsed coal column based on a result of the imaging performed on the reflected waves. However, the reflected wave is a macro-scale geological element response, and usually can only solve a problem of exploring a geological body with a spatial distribution greater than one seismic wavelength, but it does not well identify small-scale geological information, such as the collapsed coal column. Therefore, the seismic wave imaging technique developed for reflected waves is ineffective in imaging small-scale geological information such as the collapsed column, and thus cannot well identify the small-scale geological information such as the collapsed coal column.